I'm no expert, but I did come across this, which sounds promising:

"Soil Carbon Pools, Nitrogen Supply, and Tree Performance under Several Groundcovers and Compost Rates in a Newly Planted Apple Orchard.

Source: HortScience . Dec2011, Vol. 46 Issue 12, p1687-1694. 8p.

Abstract: This study evaluated the effects of in-row groundcovers (bare ground, brassica seed meal, cultivation, wood chip mulch , legume cover crop, and non-legume cover crop) and three compost rates (48, 101, and 152 kg available nitrogen(N)/ha/year) on soil carbon (C) pools, biological activity, N supply, fruit yield, and tree growth in a newly planted apple (Malus domestica Borkh.) orchard. We used nonlinear regression analysis of C mineralization curves to differentiate C into active and slow soil C pools. Bare ground and cultivation had large active soil C pools, 1.07 and 0.89 g C/kg soil, respectively, but showed little stabilization of C into the slow soil C pool. The use of brassica seed meal resulted in increased soil N supply, the slow soil C pool, and earthworm activity but not total soil C and N, fruit yield, or tree growth. Legume and non-legume cover crops had increased microbial biomass and the slow soil C pool but had lower fruit yield and tree growth than all other groundcovers regardless of compost rate. Soils under wood chip mulch had elevated earthworm activity, total soil C and N, and the slow soil C pool. Wood chip mulch also had the greatest cumulative C mineralization and a high C:N ratio, which resulted in slight N immobilization. Nevertheless, trees in the two wood chip treatments ranked in the top four of the 13 treatments in both fruit yield and tree growth. Wood chip mulch offered the best balance of tree performance and soil quality of all treatments. [ABSTRACT FROM AUTHOR]"

I've also read some studies which say the opposite, for example, https://books.google.ca/books?id=uMIXAAAAYAAJ&ots=627Q7jWJwL&dq=wood%20mulch%20nitrogen&lr&pg=PA17#v=onepage&q=wood%20mulch%20nitrogen&f=false, which says the decomposition of the mulch and tie up the mobility of nitrogen.

On YouTube there are many gardeners supporting the benefits of wood chip mulch. I use cedar mulch myself around perennials and they seem fine. I do pull the cedar mulch slightly away from the base of plants to as not directly touch them as I've heard cedar can burn plants....

Interesting to see the contrasting sides:

http://www.sciencedirect.com/science/article/pii/S0378112712001934

http://www.oardc.ohio-state.edu/hermslab/images/Lloyd_et_al_2002_Biocycle_Mulch.pdf 

Ain't ever seen any orchard in hot dry places mulch fruit trees. The idea is to let them almost dry out with extremly well drained soil and sand. I would simply just use fertilizer like fruit tree fertilizer that has all the micronutrients you need and perhaps one or two foliar feedings through the growing Season

we have short dry summers here. Some years are wet I don't see the need to mulch unless you don't have water source. Mine is easy I use the garden hose. But in summer months I like to let the trees soil dry right out before I water again. Prunus roots rot fairly easily if I mulched I would never need to water them. Where is the fun in that :) I pride myself in watering my trees and fertilizing like this.